Draft regulator



5 M 9 A, E E N E E K L w Sept. 25,, 1923.

DRAFT REGULATOR 3 Sheets-Sheet 1 Filed Feb. 5, 1921 Qfioma-foz WilliamL'Keene Sept v.25, i923.

DRAFT REGULATOR Filed Feb. 5, 1921 w. L. KEENE 3 Sheets-Shet 2 WilliamLKeene 5 Sheets-Sheet 5 Filed Feb. 5, 1921 swam V600 WiHiaYriL-Keene.

Patented Sept. 25, 1923. Y r V UNETED STATEE @E itFlfiE,

WILLIAM L. KEENE, F WATERVILLE, MAINE;

RAFT 7 REGULATOR.

Application filed Febr'uary 3, 1921. Serial no. 442,178.;

To all whom it may concern: similar reference characters indicatesimilar 7 50 Be it known that 1,.WILLIAM L. Knenn, parts, 7 a citlzen ofthe United States, residing at Flgure 1 15 an elevation ofmy device,

Waterville, in the county of Kennebeo and showing the parts in onepoftheir operative State of Maine, have invented certain new posltions, therelative position thereof in a" and useful limprovementsv in DraftReguheatingsystem being shown in Figure 6,

lator's, of which the following is a specifi- Figure 2, a'plan of thesame, certain porcation. tions being omitted, I My said inventionrelates to a draftregu- Figure 3, a detail of acircuit breaker and latorfor controlling the fire used in operatstop,

ing steam generators, thus determining the Figures 4 and 5 are detailsof parts shown 60 steam pressure in such generators and reguin Figures 1and 2, and I g lating the heat given off by them in opera- Figure'6, anelevationshowing the devicetion. Such draft regulators are peculiarly inits relation to a furnace.

adapted for use in connectionwith steam or in the drawings referencecharacter .10

hot water heating systems for dwellings, but indicates a furnaceof asteam or hot water 65 their utility is not limited thereto. heatingsystem, which is connected to a It is an object of my invention toprovide pressure operated device 11, here shown as a draft regulatorwhich may be controlled of the diaphragm type to be operated by by thepressure of the steam but which is steam. In use any device which willproduce 7 A' further object of my invention is "to 'perature;

operated by means preferably mechanical satisfactory 'results may besubstituted 7 entirely independentof the steam pressure, "therefor. suchfor. instance that in which whereby a very small variation of pressurewater actson a thermostatic tube to vary may operate to open or closethe damper. the lengthof the same according to the temprovide athermostat which may be con- 'A lever 12*is attached to the pressuredotrolled by the temperature of the air in a vice 11 in the usual wayand this lever has room to be heated and which forms an auxilconnectedthereto a rod 18- carrying, a series iary controlling means in'additionto the of collars 1e, 15 and 16. lhe rod is guided 30 pressure controlheretofore mentioned. by an opening in the support A. and a 1 Anotherobject of my invention is to probracket 17 projecting from'the" mainframe vide means whereby the damper may be p I a closed when the steam.reaches the desired The operating mechanism for the damper pressureregardless of the temperature of 18 comprises a rock arm 19 mov ed inone the atmospherein rooms to be heated. In direction by alweight. 2Q,and in the other this way overheating of dwellings is preby a chain 21connected to a crank 22 having vented. aplurality of openingsitherein"for adjust- Another object is to: provide a device of ment of the'chainilhe crank 22 is mounted the character described in which the 0011- on ashaft 24 carrying at. its opposite end trolling mechanisms may beset soas to be-a crank 23 connected bya-chain 21 to theinoperative and whenthey are so set the'furnacedoor 23' and thisshafthas fixed v draft willbe cut off. I 1 thereon a pinion 25 meshing with agear 26 A furtherobject of my invention is to on ashaft 27; The shaft 27-has a sprocket]provide a device of this kind which can be gear 28 overwhichpa sses asprocketv chain 45 operated either by the steam pressure alone 29having'at oneend-a weight 30 'andjhaving I or by steam pressure androomheat-coinnear the other end an adjustable stop '31 bined. i V whichfmay take the form offa bolt passing Referring to the accompanyingdrawings through a link of the 'chain 29 and havingl which are made apart hereof whi h a nut threa edion one thereof. ,The

sprocket is'connected to the gear 26 by apawl 82 engaging" a ratchet 33and intended to permit the sprocket to rotate freely in one direction.In this manner the sprocket is adapted to be driven in'one direction bythe Weight 80- until its. limit of IIIOYlfIYl-Ei'lt 7 reached and thesame may readily be re-set carries at its end a pin l lcomprising endportion or apiece about the shaft. 7

Adjacent the pin 44 is a pivoted armature in add lion rod 47 underpressure ofiits p iew 5:2 is

by a pull on the opposite end or" the chain. Adjacent the pinion a gear8- is fixed to shait Q L-and this engages a pini on a shaft 36 whichalso carries a gear 37 engaging a pinion 38 on a shaft 39v Sha -ft 39has a gear 40 meshing with a pinion 41 on a shaft 42, thelatter carryinga tan brake 43 of the usual type. All these shafts are ournaled in theframe workB and the shaft 4-2 projects through the frame work and the ofSPIlIlg'WlIe weuno.

having a projecting portion forming a stop by means of which thearmature acts as a detent to engage the pin to prevent re- A pair ofelectro tation of theshatt e2.

the armature in one direction and a red at pivoted at one end to thearmatureis im pelled' in a direction to Withdraw the armature from theelectro-magnets by a light spring located in cash :7 48. .The shaft 2%to ture out 0:? cngagementwith pin and'has a-not/ h adapts-ti to be en"I; to stop rotation. i the bu the weight'motor by engagement with theupper lever hav-ing a hook to enxhe-pin' and the lower lever caving aned end portion-Rvhich the pin may e [The levers ailapi edito be heldl'iGfiCli position where-"they may engage pin i:t'when the pro ection orriser on either lever. dropsv into ti'ielnetch' '51. on disk 51.

. at. to e titted outot 1-5 :projectlng tron'i the coliar tion by a p tal.

wardl y from.collarfil l into engagement wit lever-:53 .tolift the same'ifvhen vthe notches otdiskblarie properly POSl'DlOIlGQl 7 noperativeposition by the disk 51 but spring pres'sed pin i l extends un Lever 53carries a spring which constitutes one member of a circuit closer, theother mei'nbcr being an adjustable bin 55 mounted in a bracket 56 onsupport- A. A second circuit breaker is located at one end of the frameand comprises a member 57 pivoted at 57 and contacting'with the head oipin 58 said member having a handle 80. A slidable member 59 pivoted tothe movable element 57 has at its turther end an en larged head with anupwardly extending portion 60 adapted to engage the lowerend ot' thearmature and draw the detent d7 away from disk 49. I

At any convenient place, as onthe wall of a rooui to be heated is placeda thermostat comprising a base 61 carrying a thermostatic u'ieinber62hai'ing a bent portion extending,

from its point of attachment to the base and terminatingin astraightportion. Near the end of the straight portion is a contact member havinga head 64in alinement'with its pivot or varying its posit on,andcarrying a :-i(i]i]&li'i1'i screw (53- ior determining; the

limit to which the room temperature may fall. The member 62 is somade asto con tract when the tempo 'ature "tails Wherebyit may n she contact,with the adjusting screw 33. When this-thermostat is not/to be used kthe circuit and retract the'armature. thcr circuit breaker is providedin juxtaposition to thesprocket chain and'com prises a lever 65 pivotedon an insulatedbolt 6 oi :onducting' material. and adapted .to

contact with another insulated bolt 67 "of Sili'illtll material on theframe. The lever 65 carries a pin 71 extending beneath a "pawl 72 alsopivoted on screw 66. The rodG8eX- the circuit breaker at 57 may beoperated to I tends ddwnward from lever 65 and carries at 1' Illa Imovement of pin 71 j lowers the pawl 72 ,whi h. upon engagement with thenotch in I disk 'Zdon shaft 24, stops the rotation of the various shaftsof the device. This prevents overtravel of the chain whereby it mightrun the s n-ticket. and the interrupt on ot the circuit prerents wasteofCurrent. A wire 7 2 connects the screw 67 to one terminal of the roomthermostat. A second wire 7 5 extends from screw 6': to Le screw 76v onthe main me which supports at its otherendthe e r .This casin j iselectricallyronneetcd codisk' l i) by-a-leat' spring 77. r

. ltdesired. I may provide. a latchQatTZ,

and the room thermostat 61 is shown in the V drawings andparticularly inFigure 1. In

this figure the current may pass from the batteryto the-roomvthermostat, thence by wire 74-,screw 67', pivoted "arm65, screwfio',wire 75, screw 76, casing 48, spring 77, and

disk-49 to shaft 24; and'from, this shaft, through disk 51 detent 53,spring 54, pin 55' and bracket '56 to WHQ'IS. From wire 78 currentpasses to electro-magnets- 46 thence to pin 58 and circuit closer 5t andback to the battery by wire 79. W 1th the parts in the position shownthe damper-is closed and the furnace door which moves as the damper isalso closed and the device is subject'to variations in room temperatureand also to the action of pressure device 11- in the following manner;when the thermostat 11 draws the rod 13 down sufficiently-to close thecircuit at 54 55 and with draw detent from notch 51, the shaft 24becomes subject only to the electrical mechanism controlled by the roomtemperatureyii e., it is held from rotationby the detent on armature 45.Thedamper cannot be opened until the room temperature has fallensufiiciently to close the circuit at'63 when the electromagnetwill beenergized and will retract armature 45 and its detent, thus permittingthe weight 30 to act as a motor to operate the shaft 42 through thetrain of gearing-untilnotch 51' comes in position for engagement by theriser on-detent 52,' i. e. until the shaft:24 has made a half reyolutionand. the damper til the thermostatll raises the rod 13: i.

until thie temperature of the hot water heating system, or thetemperature and pressure of the. steam'heating; system. or'likccoiitrolling feature has risen sufliciently'to actuate the thermostat asindicated; whereupon detent 52'is raised by pin 15 and the weight 'motorcomes into action again to rotate the shaft 24 and close the damper, the'disk 51 now holding the armature away 'lro m pin '44 by means of-r'od47 and the circuit bein broken at 5.0. Rotation ceaseswhen-notch '51comes: over the stop-lug ciifldetent 'w,

' detentis which is forced upward by'springpressed pin 14' and the endofthedetent-now en-H gagesipin 44 ,to halt the-action of the weight 1 7-motor..

VVhen detent 53 engages 44' disk 49 has revolved sotar that rod 47 isonthe verge of dropping into; the notch on the disk. VVhen' now the rod13gfalls. due to decreasing steam pressure or the-like,J-sotaras tofremove-detent 53, it sin'iultaneously-permits 1 :shatt24 to-rotateuntil rod 47 falls-into its notch, orawingr armature 45 ll1tSO-POSltlOT]to engage, pin- 44aiid stop such rotation, and also closes the c rcuitof the statat 54, 55. This completes the cycle.

Assuming that the device to be oporiiti' by steam pressure alone thecircuitinay be broken by actuation ofthe circuit-closer 57.

Thereupon, the dam-per being in its;close.-:i position, :as

.sho'wninFigur-e 1, will remain I so until the action-0i the pressuredevice 11 lowers the rod 13 due. to the lowered tenr room .tlierino-'perature of tllQWELiIBl (or other-controlling condition) to such adegree. that the lever 53 falls so far as to'relea se the pin 44 troi'ndisk 51 has rotated so far that the: leverr52 is permitted to fall bv'engagement of its lu f with notch '51 whereupon the pin 44- is;

caught by thehook on detent 52 and held I against rotation, the arm22pointine down ward from sha t 24 and the damper 18 being in openposition. The parts will'now stav in this relation while the fire buildsup andthe steam pressure increases until the pin .15

lifts .detent 52 to, releasepin 44{w '-enth e weight 30' resume-s itsoperation and 'HTUS arm 22 to the position shown in" Figure 1.

lever being: actuated by the spring'pressed ;,7iii 14. to enter its lugainthe'notch of disk 51'whereby'its outer end is po'sitionedto engage.the pin 44 and hold it until the pre sure device 11 again lowers-therod 13. ":Tbe .lug of the detent which is out oi": acti on rides on theperiphery of the disk 51 whereby-tho pin 44.w r i The-purpose ofthespring pre sed pin14 isto providelost motion connection bet'\veen vicemay be mentioned the fact that is not dependentonthe. steam pressuretorfactuadctent with the movement oitv restrained from engaging the tionof thedampcrtthe weight motor being arranged to actuate the samepositively and the steam pressure serving merelyto actuate iYlQ'Q'Q-IlllZG device which controls thenction of-the weightin otor; thatsince-it does not depend on steam pressure or water'heat' I or'the intemperature; that due to its construction.

"the damper will be closed when the device is put out of operation as anentirety, and

heat is sufficient whether the room tempera ture has by that time risento the desired heightor not. 7 w V Various modifications of my device orof parts thereof will occur to those ski ledin the art, and I do notlimit myself to the" precise form shown in the drawings, nor-to theparticular use described, the scope of the invention being defined inthe ,appended claims} 3 i As an exainple of such n'iodifications thethermostatic element inay consist of a rod "or tube projecting into thefurnace itself or into the'fluid heated by the furnace, whether same bewater or air. The thermostatic controllingineans may operate on a damperWltl'lln the'smolre pipe or a check draft damper or it may operate on avalve controlling ingress of heated air, or steam or any deviceequivalent to any of the above meansf Various other motors; e.;g.,springmotors, maybe substituted for the weight motor shown. a

Having thus fully described my said invention what I ela-i'mas new anddesire to secure by Letters Patent,'is:

1. In combination, a pressure controlled device, a rod extendingupwardly therefrom,

a damper, arotary shaft tomove the damper,

a motor for rotating: the shaft, means. for

locking the shaft to hold the damper open [or closed comprising a pairof-detents and means on said upwardly extending rodfor moving saiddetents, substantially .as set forth.

2. In combination, a shaft, means tending torotate'thesame in onedirection, a temper attire-controlling device connected to the shaft andadapted to be operated by rotation of the: shaft, means to lock thedevice and its.

driving means in a predetermined position, a disk on said shaft to holdsaidjlocking means inoperative and a pressure controlled meansco-operating with the disk'to control the locking means, substantiallyset forth.

In combination, a shaft, means tending to rotate the same in onedirection, a temperature-controlled" device connected] to the shaft,means to lock theshaft in predeter- 'mined positions comprising a secondshaft geared to the first, and having a finger extending therefrom ,':apair of Jdetents adapted to engage the finger alternately, and meanstocontrol the detentsincluding means a ttheaboil'er, substantially asjset'i with thedisli to control} the locking tached jfO forth. 7

' a, lnscombination, a shaft, means tending to rotate} the same none'd1rect1'on; a'tem-- perature -controlling device connected to theshaft, means to lock the shaft in predetermined positions comprising. asecond shaft geared to the first, and having a finger extendingtherefrom, a pluralityfof detents adapted to engage the fingeralternately, and means on the first'shaft for holding the'detents out ofengagementat predetermined times, substantially as set forth;

I 5. In combinat on, ashaft,meanstending to rotate the same, in onedirectiomt-a temiperaturerontrolling'device connected to the shaft,means to lock the shaft in predetermined. positions comprising a-second'shaft gearedto the first,rand having a finger extending therefrom, aplurality of "detent-s 'adaptedto engage the finger alternately,

means onthe first shaft for holding some of the dctents outof'engagement at predetermined times, and an 'electro-ma gnet,adapted y.85

to move one of the detents out ofengageinent'with the finger at anothertime, substantially 'as set forth. 5 1

6. In combination, a shaft, means tending to rotate thesame,zin onedirection, atempei'ature-controlling device" connected to the shaft,means to lock the-shaftin predeteri'iiiiiedpositioiis coinprisng asecond shaft geared to the first, and having a finger extendingtherefrom, a plurality of detents adapted to engage the fingeralternately, an elect ic-magnet for disengaging one of Sitld detentsfrom the finger, ,a thermostat for con.-

trollin its action and means connected to V the boiler whereby theremaining detents' may be released, substantially as set forth.

1n confibinat on, a shaft, meanstendiug to rotate the same in onedirection, a'temperatnre-controlling device connected to the shaft,means tolock the shaft in predetermined positions comprising a; secondshaft geared to the first, and having a finger e tending therefrom, apair of deten s adapted to engage the finger alternately,means tocontrol the detents including" a pressure operated device, a rodattached thereto and havingiaqfixed abutmei'it and a-yieldable abutmentfor engagement with the respective detents, and anotched disk on thefirst shaft adapted to co-act with said rod to control said detents,substantially as set forth. S. In combination, a shaft, means tending torotate the same in'one direction, attemperatui;'e-controlling deviceconnected to the shaft and adapted to be operated by rotation of'itlieshaft, a second shaft gearedto the first" and having a projecting pin,de-

tents to'en'gage said pin alternately to pie 7 vent'rotation of theshaft, a' disk onthe first shaft having a notch for alternately engagingprojections on the respective detents, and apressure controlled device.co-o'peratmeans, siflbstatially as set'forth; V i V V 9 i o t n, shatrm ans; tendin to rotatethesame in onedire'ction, a tempen detentsattire-controlling device connected to the shaft and adapted to beoperated by rotation of'the sh: first medium co-operating with the diskto control the loclnng means;substantially as set forth. 7

10. in a heating system, a shaft, means tending to rotate the same inone direction, a temperatu-recontrolling device connected to the shaftand adapted to be operated by rotation of the shaft, a second-shaftgeared "to the first, a plurality of locking means whereby said secondshaft and its connected mechanism may be locked inpredeterminedposit-ions, meanscontro'lled. from a source of heat forreleasing the one of said locking means, and means controlled by thetemperature of "a room for releasing another locking means,substantially as set forth.

'11.Incombination, a shaftfmeans tending to rotate the same in onedirection, a temperature-controlling device connected to the shaft andadapted to be operated by rotation of'the shaft,'a second shaft gearedto the first, means whereby said second shaft and its connectedmechanism may be locked in predetermined positions, auxiliary lookingmeans acting on said second shaft in "another POSllZlOIl and-temperature-controlledV means for releasing both sets of locking means,substantially as setforth.

12. 111 a. heating system, a snaft means tending to rotate the same inone direction,

a temperature-controlling device connected to the shaft and adapted tobe opened fa'nd;

closedv by rotationof the shaft, a second shaft'geared to the first, aplurality of look ing means whereby sa d second shaft and 1ts connectedmechanism 'may be locked in prodetermined positions, means controlledfrom a source of heat forreleasmg theone of locking means, an armatureconnected to the second locking means, and a thermostat electricallyconnected to. operate-said armature, substantially as set forth.

18. In combination a temperature controlling device and means to operatethe same comprising a shaft, a finger thereon, a plurality of holdingdevices forthe finger. means to retract one of the holding devicescomprising an electro-magne't, a thermostat in-circuit therewith, andmeans to move another holding means toward the finger and thereby, breaksaid circuit, substantially as set forth.

14. In combination a temperature-controlling" device and means tooperate the a second shaft geared to the same comprising a shaft,afinger themes,"

a detent to engage the finger, an electromagnet toret-ract the detent, asprocket gear connected to'drive said shaft, a chain onthe sprocket,anweight on the chain, yieldable means to limit the movement of thechain by the weight,and a circuit breaker adapted to'be operated by saidyieldable means to break the circuit of said electro-magnet, sub-"stantiallyas set forth.

' 15.111 combination, a temperature-controlling device, and means. tooperate the same comprising a'weight motor, and a train of gear ng,means'for engaging a'shaft of said-gearing to stop the movement thereof,

means'to engage another shaft to lock the motor against rotat1on,'sa1dmeans, being,

normally held out ofopera'tive position and being restored toaction bysaid motor near, the limlt of its trave1, substant1ally as set forth.

16. A heating system comprising a tem-" aerature-controllin '"device 'afurnace and b 7 a I means for operating said devicecomprisin'g athermostat adapted tobe placed in a room to be heated, and; a 'secondthermostat c onnected to the furnace and adapted to operate thetemperature controlling "device inde" pendently of the first thermostat,and means whereby the first thermostat be rendered inoperative,substantially as set forth.

'17. A heating system comprising a tem perature-controllingfdevice, afurnace, andf meansfor operating salddevice" comprismg a thermostatadapted {to be placed in a room to be heated, and a second thermostatconnected-to the furnace and adapted to control said device inconjunctionwith' the first or independently thereof, substantially"asset forth. 1

18.111 a heating system, a furnace, a:-

damper, means for actuating the damper, meansto lock the damper in openor closed" position, a pressure device connected to the{' furnace, vmechanical. means connected to the pressure device for controlling thelocking means, and means whereby the .pressuredevice may be'putoutofaction, substantially asiset forthi" y '19. In a heating system, afurnace,'a

.damoer' means foract-uatincr the dam er. .L 7 b 1 means to lock' thedamper in open or closed position, a pressure device, a vertically movable rod connected to the pressure device for: controllingthe locking'means, arollar. on." the rod and means to hold the rodinclevatedposition whereby th'e'damper controlqling mechanism isrendered inoperative, sub stantially' as set forth.

2 0. In: a heating system, a furnace, a damper, means for actuating thedamper comprising rotating shaft, a pair of 'de tents adapted to engagethe shaft in alteration to lockthe damper in open or closed position, apressure controlling devlce connected to the furnace, a rod on thepressuredevice adapted to release the detents from saidshaft and means'Whereby the rod may be held in inoperative position, such meanspermitting the damper actuating mechanism to close the damper,substantially "as set forth. 7 i

21 In a heating system, 7 a furnace, damper, means for actuating thedamper, a plurality of detents to lock the damper 1n predeterminedpositions, a room thermostat,

an electro-magnet controlled thereby for re leasing one of said detents,a furnace pressure device, a rod actuated bythe pressure device forcontrollingthe remaining detents, means for locking sald rod 1ninoperative positioniwhereby said rod also breaks the circuit of-saidelectro-magnet and permits the damper actuating means to' close thedamper, substantially as set forth.

. 22. In combination, a temperature con: j trolling device and meansto'operate the same. comprising a shaft,a finger thereon,

means for holding the finger against rota- ,tion, an electro-magnet forretracting said holding means and a circuit closer adapted to deenergizesaid electromagnet and simultaneously Withdraw. the holding means,substantially as set'forth. V p 7 p 28. in a heating system, a furnace,.a damper, means for actuating the damper andvthe furnace door, means tolock the damper and thefurnace door in open or closedip osition,pressure controlled device connected to the furnace, means connected to,

J the pressure device for controlling the lock-' ing means, andmeanswvhereby thethermostat may, be ,put out of action substantially asset forth.

24:. ln'a'heating system, a furnace, a damper, means for actuating the;damper V and. the furnace" door, means to lock the damper and the.furnace door in open or closed/position, a thermostat, a verticallymovable rod connected to the thermostat for controlling the lock ngmeans, a collar on the :rodand means to hold the rod in elevatedQQSlUOIl av-hereby. the controlling means for the damperand the furnacedoor is rendered inoperat ve.

. 25 111221, heating system, a draft regulating device, mechanical means"for opening and'closing said device, connected to the furnace fornormally controlling said mechanical means, a room thermostatsupplementing the action oft-he second said means to prevent openingofthe draft until the room temperature falls to a predetermined extent, anelectric circuit for the room thermostat, and meansactuated by thefirstnamed thermostat for making and breaking saidcircuit, substantiallyas set forth. v

26. In a heating system, a furnace, a draft regulating'device thereon,and means gov= erning said devicecomprising a rotary shaft memesconnected to; the draft controlling device, a eight motor for rotatingthe shaft, temperature-controlled means to put the motor into and out ofaction, andmeans to engage the shaft to stop the operation of thecontrolling devices with the draft off as the Weight motor approachesits limit of action, substantially as set forth. h '27. A heating systemcomprising a furnace, draft regulating 'means' therefor, a

its. 'n otor for operating said draft regulating moans, means controlledby the heating medrum to govern themotor, temperature con trolled meansadapted to look the motor 'Whereby the motor cannot operate to increasethe draft until; acted upon by the,

temperature controlled means, substantially as set forth. 5

28.1 1 heating system comprising a fur 'nace, a damper, a motor foropening an d closing the damper and the furnace door, means connectedtothe furnace to mechanically operate to cause the motor to close thedamper, 7 temperature controlled means adapted to lock the motor; insuch position whereby the'motor cannot;operatetoopen the damper untilacted upon by the tem- 1 perature controlled means,substantially as nacea damper a motor for openin and.v

7 .L n b closing't-he damper and the furnace door, temperature}controlling device, pressure controlled means connected mechan-ically tothe furnace and the motor "whereby" upon :reaching a predeterminedpressure the said pressurecontrolled means alsoopera-ting the motor-toplace the motor entirely under-the. control of the temperaturecontrolling device when, and only vvhen thepressurehas dropped to apredetermined point, said tern perature controlling] devicethen. "beingadapted to operate the motor to openithe" furnace .door andainper,substantially as 1 set forth. c

' 31. A heating system comprising.a rurnace, a damperya motor foropening and closing the damper and the furnace door, a temperaturecontrolling device, pressurecontrolled means connected inechanioal'ly tothe furnace and the motor whereby upon. reaching :a predeterminedpressurethe said pressure controlled means also operating the motor tolace the motor entirely under the.

control'of the temperature controlling device When and only when thepressure has dropped to a predetermined point, said tem- In Witnesswhereof, I have hereunto set perature controlling device then being myhand and seal at vVaterville, Maine, this 10 adapted to operate themotorto open the twenty-fifth day of January, A. D.'ninefurnace door anddamper, and means Whereteen hundred and twenty-one.

by the temperature controlling device may YVILLIAM L.-KEENE. [1,. s.]

be eliminated leaving the motor at all times Witnesses: under thecontrol of the pressure control- ALLISONCHOATE NIoKERsoN,

ling means, substantially as set forth. WELLINGTON A. BLAIR.

